<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
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    <title>Document</title>
    <script src="http://unpkg.com/vue@next"></script>
</head>

<body>
    <div id="root"></div>
</body>
<script>
    let app = Vue.createApp({
        setup() {
            const { reactive, toRefs, watchEffect } = Vue
            const Obj = reactive({
                name: 'a', name2: 'b'
            })
            watchEffect(() => {
                console.log(Obj.name)
            })
            const { name, name2 } = toRefs(Obj)
            return { name, name2 }
        },
        template: `
        <div>
         <input v-model="name"/>{{name2}}   
        </div>
        `,
    })
    app.mount('#root')
</script>

</html>